Flexible pipe joint having an annular flexible boot thermally or chemically insulating an annular elastomeric flexible element

Abstract

A flexible pipe joint has a body and an annular elastomeric flexible element flexibly coupling an extension pipe to the body for pivoting of the extension pipe with respect to the body. The flexible pipe joint also has an annular flexible boot for thermally or chemically insulating the annular elastomeric flexible element from the fluid flowing through a lumen of the flexible pipe joint. The annular flexible boot encircles the lumen, and the annular flexible boot has a first annular end attached to the extension pipe and a second annular end mounted so that pivoting of the extension pipe with respect to the body causes a flexing of the annular flexible boot, and a majority of the annular flexible boot has a shape conforming to shape of neighboring components of the flexible pipe joint.

Description

RELATED APPLICATION[0001]The present application claims the benefit of James G. Patrick et al. U.S. Provisional Application 62 / 168,707 filed May 29, 2015 entitled “Thermal or Chemical Insulating Boot for Flexible Elements,” incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to an annular flexible boot for insulating an annular elastomeric flexible element in a flexible pipe joint from thermal or chemical exposure to fluid flowing through the flexible pipe joint.BACKGROUND ART[0003]Elastomeric flexible elements are often used in the oil industry in flexible pipe joints for coupling or supporting segments of a pipeline or riser. A limitation of the elastomeric flexible elements is reduced performance when exposed to heat from fluid flowing in the pipeline or riser, and to chemicals in the fluid. A conventional way of dealing with this limitation is by using a two-stage bellows.[0004]For example, as described in Whightsil, Sr. et al. U.S. Pat. No...

AI Technical Summary

Benefits of technology

[0006]A two-stage bellows is the typical way of providing thermal or chemical insulation of an annular elastomeric flexible element of a flexible pipe joint from fluid flowing through the flexible pipe joint. Depending on the particular shape or configuration of the flexible pipe joint, an annular flexible boot, as further described below, will provide thermal or chemical insulation of the annular elastomeric flexible element and will provide one or more advantages in comparison to a two-sage bellows. For example, the annular flexible boot may be more economical to manufacture than a two-stage bellows, and may require a smaller space to be reliably installed or operate in a reliable manner, and may be less sensitive to buckling under certain loads, and may reduce a pressure head on the flexible joint. In many cases, the annular flexible boot can be used as an alternative to a two-stage bellows or in addition to a two-stage bellows, and by specifically adapting the shape of the boot to the type of flexible pipe joint on which it is used, the boot will improve upon the benefits of a two-stage bellows.

[0009]In contrast to a bellows, a majority of the annular flexible boot is shaped to conform to neighboring members of the flexible pipe joint. This provides a more compact size for the flexible pipe joint, and a reduction in weight of the housing of the flexible pipe joint. In many cases, a majority of the annular flexible boot may be mechanically supported by contact with the neighboring members of the flexible pipe joint.

[0011]In a first example, the annular flexible boot has a cylindrical shape conforming to a cylindrical central lumen of a flexible pipe joint. The cylindrical boot functions as a central sleeve for containing and sealing the fluid medium within the central lumen, and chemically and / or thermally insulating the elastomeric flexible element from the fluid medium. Each end of the cylindrical boot may be sealed against an end of a respective extension pipe or attachment member. The sealing of each end of the cylindrical boot may include use of an adhesive boding agent and use of a mechanical connection to add to the effectiveness of the seal. The cylindrical boot may also pass through a center ring of a pressure isolation unit including two diametrically disposed coaxial secondary elastomeric flexible elements coupling the centering ball to an extension pipe and an attachment member, and in this case each end of the cylindrical boot may be sealed against a respective end of the pressure isolation unit, or against an end of a respective extension pipe or attachment member.

[0013]In a third example, an annular flexible boot has a body portion including an outer toroidal shaped portion and two inner portions conforming to the shape of an end of an extension pipe, attachment member, or center ring. The outer toroidal shaped portion is disposed between the two inner portions. For example, each inner portion includes a spherical portion neighboring the toroidal portion and having a shape of a spherical zone, and an end portion for sealing attachment to an inner surface of the extension pipe, attachment member, or center ring. The sealing of each end of the toroidal boot may include use of an adhesive boding agent and use of a mechanical connection to add to the effectiveness of the seal. The end portions may be cylindrical, and seal against an internal cylindrical surface of the extension pipe, attachment member, or center ring. The toroidal boot is manufactured by forming the individual sheets of impervious material and fiber reinforced elastomer layers into a toroidal shape, which is designed to fit between an end of the extension pipe and an end of an attachment member or center ball. In operation, the toroidal boot accommodates articulation of the flexible pipe joint by rolling over an inner ring of the elastomeric flexible element, on one side, and over the surface of the end of the attachment flange or center ring, on the other side. To contain the fluid medium under high pressure, the cavity behind and encircling the toroidal boot can be filled with a hydraulic fluid compatible with the elastomeric material of the elastomeric flexible element, in order to provide mechanical support to the toroidal boot. To contain the fluid medium under low to intermediate pressure, fiber reinforcement of the toroidal boot may sustain the pressure load without the support of hydraulic fluid.

Problems solved by technology

A limitation of the elastomeric flexible elements is reduced performance when exposed to heat from fluid flowing in the pipeline or riser, and to chemicals in the fluid.

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